POS0960 INCREASED INCIDENCE OF SJÖGREN’S SYNDROME IN THE FEMALE PATIENTS WITH HASHIMOTO THYROIDITIS: A LARGE PROPENSITY SCORE-MATCHED COHORT STUDY
Authors: Y. Du, Q. Tong, R. Cui, Q. Wang, S. I. Wang, J. Wei, S. M. Dai
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> In clinical practice, we notice that <b>S</b>jögren's syndrome (SS) usually coexists with Hashimoto thyroiditis (HT). There were a lot of case reports regarding the coexistence of SS and HT. <h3>Objectives</h3> To determine whether Hashimoto thyroiditis (HT) is a risk factor of Sjögren's syndrome (SS) longitudinally in a very large cohort. <h3>Methods</h3> We conducted a cohort study using TriNetX (Cambridge, MA, USA), a global federated health research network that provides real-time electronic medical record datasets. The diagnosis of HT or SS was based on ICD10 codes. We analyzed the incidence of newly diagnosed SS in the female patients with HT within ten years. Propensity score matching including 38 factors was performed to adjust for demographic variables, comorbidities, and medication use. Kaplan-Meier analysis was used to estimate the probability of the outcome of interest. The hazard ratio (HR) and associated confidence intervals (CI) were calculated along with the proportionality test using R's Survival Package v3.2-3. <h3>Results</h3> We identified 101,590 female patients aged 20-64 years with HT among 54,801,179 patients in the database with ≥ 2 visits between 2012/01/01~2021/12/31. Of these patients, 100,027 were included after exclusion those diagnosed with SS before index date. The control cohort was selected from those females without thyroid disorders or related therapy. After 1:1 propensity score matching, 100,027 patients in either HT or control cohort were analyzed for comparison. After one-year follow-up, the incidence (0.51%) of new cases of SS in the HT cohort was higher than that (0.098%) in the control cohort (HR 4.324, 95% CI 3.483-5.368). During the study period, higher incidence of SS in the HT cohort (1.16%) than in the control cohort (0.36%) was found (HR 3.557, 95% CI 3.151-4.016). Increased incidences of SS in HT cohort were also confirmed in the subgroups of different ages, races and smoking status, and subgroups with or without diabetes mellitus, overweight/obesity, sleep disorder, depression, hypertension and asthma (Figure 1). <h3>Conclusion</h3> This study underlines that HT is a risk factor for developing SS, which implies that SS and HT are 2 autoimmune diseases closely related, and may share some underlying pathophysiological mechanisms. <h3>References</h3> [1]Caramaschi P, Biasi D, Caimmi C, Scambi C, Pieropan S, Barausse G, Adami S. The co-occurrence of Hashimoto thyroiditis in primary Sjogren's syndrome defines a subset of patients with milder clinical phenotype. Rheumatol Int. 2013 May;33(5):1271-5. doi: 10.1007/s00296-012-2570-6. [2]Hansen BU, Ericsson UB, Henricsson V, Larsson A, Manthorpe R, Warfvinge G. Autoimmune thyroiditis and primary Sjogren's syndrome: clinical and laboratory evidence of the coexistence of the two diseases. Clin Exp Rheumatol. 1991 Mar-Apr;9(2):137-41. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.